1. Field of the Invention
This invention relates to the field of assaying chemokine receptors and the preparation of agonists and antagonists to chemokines, in particular, antibodies to these chemokine receptors.
2. Description of Background and Related Art
While interleukin-8 was initially identified as a chemoattractant for neutrophils, and was known to bind a receptor on neutrophils (Samanta et al., J. Exp. Med., 169: 1185-1189 (1989); Besemer et al., J. Biol. Chem., 264: 17409-17415 (1989); Grob et al. J. Biol. Chem., 265: 8311-8316 (1990)), it has in addition a wide range of pro-inflammatory activities including the stimulation of degranulation and the upregulation of the cell adhesion molecule MAC-1 and of the complement receptor CR1. Oppenheim et al., Annu. Rev, Immunol., 9: 617-648 (1991).
IL-8 is secreted by many cell types in response to pro-inflammatory stimuli such as IL-1.beta., TNF, and endotoxin, and is a member of a family of pro-inflammatory cytokines with a variety of biological properties including selective leukocyte chemotaxis and activation. These cytokines form a superfamily, originally referred to as the platelet factor 4 superfamily (PF4A), and now referred to as the chemokine superfamily, that has been divided into two classes based on whether the first two conserved cysteine residues are separated by an intervening amino acid (C-X-C), or whether they are adjacent (C-C). The C-X-C class members include, for example, melanocyte growth stimulating factor (MGSA), platelet factor 4, and IL-8, while the C-C class includes RANTES (Regulated on Activation, Normal T Expressed and Secreted) and monocyte chemotactic peptide-1 (MCP-1).
The IL-8 receptors are members of the superfamily of seven transmembrane, G-protein linked receptors. Taylor, Biochem. J., 272: 1 (1990). This family of receptors includes several hundred different receptors among which are the .beta.-adrenergic receptor (Strader et al., FASEB, 3: 1825 (1989); Dixon et al., EMBO J., 6: 3269 (1987)), the muscarinic and cholinergic receptors (Kubo et al., Nature, 323: 411 (1986); Peralta et al., EMBO J., 6: 3923 (1987)), the C5a and fMet-Leu-Phe receptors. Two types of IL-8 receptors have been described: type A (IL8R-A) (Holmes et al., Science, 253: 1278 (1991)) and type B (IL8R-B) (Murphy and Tiffany, Science, 253: 1280 (1991)) receptors. These two types of receptors share 77% amino acid identity and have 29-34% sequence homology to C5a and fMet-Leu-Phe. Holmes et al., supra. IL8R-A has a high affinity (2 nM) for IL-8 only, while IL 8R-B has a high affinity (2 nM) for both IL-8 and MGSA. The cell function and expression level of each receptor has yet to be determined.
It is an object of this invention to identify and prepare antibodies to the IL-8 type B receptor.
An additional object is to provide a method for treating or preventing an inflammatory response in a mammal using an antibody to such receptor.
These and other objects of this invention will be apparent from the specification as a whole.